The money making process seems to progress well from the feedback I've received so far. Just make sure you buy the Bar and upgrade it asap, that's where the money is.
Personally I've played this game three times and I've always had trouble with money after a certain character has an accident and you need to pay $2000 I believe to fix them. Because also around that time (or at least around the time in my playthrough) you're given the opportunity to buy a really expensive elf, and losing $2000 makes it so much harder. I upgraded the bar to the max and it still took a long time to make enough money to buy that elf.
I had the same problem in my first playthrough. Second time, after following the advice I got to focus on the bar as early as I could, I got closer but still ended up being in debt after the aforementioned accident. Third time, I found that the best way is - combined with the general advice about the bar - to simply limit yourself to interacting with just one of the girls per day once all of them have moved in. Sure, the plot may move forward a lot more slowly but I managed to make just enough money when it came to buying the elf in question.